Infliximab Infusion Patterns in Patients with Crohnʼs Disease Naïve to Biologic Therapy: An Analysis of a National Health Plan

Abstract

Purpose: FDA prescribing information for infliximab (IFX) treatment of patients with Crohn's Disease (CD) recommends an intravenous induction regimen at 0, 2, and 6 weeks, followed by a maintenance regimen every 8 weeks thereafter. This investigation was undertaken to examine the infusion intervals in patients with CD enrolled in a major United States health plan. Methods: Medical, pharmacy, and membership data were obtained from the i3Innovus database for the measurement period (Oct-2006 through Jun-2009). Study inclusion criteria were the presence of ≥ 2 diagnoses for CD (555.xx) at any time during the observation period, absence of a diagnosis for other antiinflammatory disorders, age ≥18 at index, the presence of ≥4 IFX infusions, a six month biologic treatment naïve period preceding the IFX index date, and at least 12 months of continuous eligibility post-index date. A treatment episode was defined as all infusions from the index claim to the last IFX claim in the dataset without a claim for any other biologic during that episode. Patients with IFX infusions ≥ 180 days apart were excluded from the analyses. The sample mean at each infusion interval was compared to prescribing information. Differences in adherence to maintenance infusion intervals were statistically measured by repeated-measures analysis of covariance (ANCOVA) methodology with patient demographics included as covariates. Results: Of the patients meeting study inclusion criteria (N=196), the number of infusions received ranged from 4 to 23 with a mean of 10. The mean interval (±SD) between the first and second infusion was 29 days (±24), with 60% of patients receiving their infusion within five days of the recommended target date (14 days). The mean (±SD) interval between the second and third infusion was 42 days (±21). The mean interval between each of the next 7 maintenance infusions ranged between 54 and 59 days (SDs ranging from 14-19 days), with a grand mean of 56 days (Table 1). Results of the repeated-measures analysis of covariance (ANCOVA) did not reveal a significant within-subjects effect for maintenance infusion interval (p =0.15), indicating the length of time between maintenance infusions did not change over the course of treatment. Conclusion: Data from a national health plan suggest that 60% of patients with CD received their second IFX infusion within the recommended two week interval; the remaining induction and maintenance intervals were consistent with expected intervals (i.e., at week 6 and every 8 weeks thereafter, respectively). Physicians in this particular health plan appeared to be administering IFX in accordance with the FDA-approved administration schedule for CD. Disclosure: C. Schmeikel Mueller: Employee, Centocor Ortho Biotech Services, LLC; L Denny: Employee, Centocor Ortho Biotech Services, LLC; J. Tkacz: Consultant, Centocor Ortho Biotech Services, LLC; C. Ruetsch: Consultant, Centocor Ortho Biotech Services, LLC. This research was supported by an industry grant from This study was sponsored by Centocor Ortho Biotech Services, LLC.